Drill for wells



July 28, 1931. w C; STARKEY 1,816,549

DRILL Fon wELLs Filed Aug. 30. 192B v Y INVENToR.

- Wal/,w1 (f7/115mm 5mm/fr.

BYW

TTOMEYS.

Patented July 28, 1931 UNITED STATES PATENT OFFICE DRILL FOB WELLS Application illed August 30, 1988. Serial lo. 802,894.

This invention relates to a rotary drill, and particularly to those drills em loyed for boring holes in the earth throug hard formations.

It is the object of this invention to provide cutters so formed as to overcome the diiculties heretofore experienced with respect to chattering and clogglng of the teeth.

One feature of the invention resides in the lo provision of a plurality of chisel-like cutting teeth on the cutters which are so positioned with respect to each other that one row of teeth will be in direct engagement with the substance untilthe next row of teeth comes J5 into engagement therewith, whereby the rolling action of the cutters against the hard substance will be smooth and even as distinguished from the intermittent engagement of each individual row of teeth causing chattering of the head. This is accomplished primarily by forming the rows of teeth splrally from the vertex to the base of the conically shaped cutters.

Another feature of the invention resides in the provision of a plurality of teeth in each row extending from the vertex to the base of the cutter whereb the chisel-like edges of the individual teet will be presented to the substance progressively. This arrangement 3o causes the shar corner of the cutting edge to first bite into t e substance and then be followed up progressively by the remaining cutting edge.

This gives a cuttin or slicing action as distinguished from the ammering action heretofore found in cutters of this type, and thus greatly facilitates the drilling with less vibration, wear and tear on the drill and power necessary to drive the same. Thus, cutters of this construction are given a longer life then has heretofore been obtainable.

Another feature of the invention resides in the combination of the concentric circular grooves separating the teeth in their respective spiral rows with the spiral grooves extending from the'vertex to the base separating the concentric rows, or, in other words, positioning the teeth on the cutter in spirally extending rows from the vertex to the base and also positioning the teeth in circular rows concentric with the vertex and the base. This positioning of the teeth and the `intermediate recesses prevents clogging of the cutter by givin the stream of wash water discharged therein a swirling motion as it is washed up- 5 wardly between the spiral rows of teeth. This swirlin motion, instead of only cleaning the su stantially radially extending grooves or spaces between the teeth as heretoore, is given an impellent force in the lateral direction causing a portion of the stream to diverge into the grooves between the concentric rows of teeth. Thus the stream of wash water not only cleans the substantially radial spaces, but also the concentric spaces.

The full nature of the invention will be understood from the accompanying drawings and the 'following descriptions and claim:

In the drawings Fig. 1 is a side elevation showing the lower end of a drill with a pair of cutters mounted thereon. Fig. 2 is a plan view of one of the cutters.

In the drawings there is shown an operating member or shaft 10on the lower end of which is mounted a pair of drill head sections 11 spaced apart and providing upwardly inclined Ibearings faclng each other and extending at an angle of 45 degrees to the vertical. Rotatably mounted on said sections there are provided a pair of cutters 12 which are adapted to rotate with respect to said sections and each other as the shaft 10 is rotated in the hole being drilled.

The cutters are substantially conical in g5 shape with the axes about which they rotate disposed at degrees to each other and perpendcular to the bearing surface of the drill head sections. Thus, when in operative position, the cutting faces of the cutters extend 90 parallel with each other and in the same cutting plane.

Each of said cutters is formed with a plurality of protruding teeth 13. Said teeth are provided with a chisel like cutting edge 14. The depth of said teeth increases from the vertex toward the base of the cutter and the teeth in each row are positioned with respect to each other so that their chisel like cutting edges 14 extend in a spiral row as indicated 100 at 15. Thus, between each spirally formed row of teeth there is a corresponding spirally extending recess. The teeth are also formed in rows concentric to the vertex so as to provide therebetween the annular concentric recesses 16. Y f

As indicated atv 17, wash water is discharged from the nozzle 18 of the pipe 19 into the hole being drilled for carrying upwardly therefrom about the outside of the drill the waste substance' cut from the bed indicated at 21. Any suitable means may be employed as is common in the art to rotate the headl through the shaft 10 for'causing the individual rolling action ofthe cutters on the bed `of substance indicated at 21.

It will be noted that by means of the above arrangement of the teeth, the rotation of the cutters against the hard surface will not cause a. chattering since, prior to the disenga gement of the surface by one row of teeth, p

the next row of teeth will have engaged so that thereA will bea continuous rolling effect of the chisel like edges of the teeth in the succeeding rows. Furthermore, by reason of the chisel like edges of the teeth extending spirally about the cutter, the forward corner of each chisel-like edge will be rst presented to the hard surface so as to dig therein and be followed by the remainder thereof, which will cut or slice into the hard substance, as distinguished from having the entire edge presented simultaneously and jammed into the substance as heretofore.

In addition to the above, the wash water which is forced downwardly through the drill for carrying the waste-substance upwardly therethrough will normally pass upwardly between the spiral rows of teeth for cleansing the same and, by reason of the change of direction of the stream caused thereby, some of the water will be deflected into the concentric recesses between the teeth and forced therethrough for cleansing between those rows as well as the others.

I claim:

A rotary drill having a pair of conical cutters each mounted thereon to rotate on axes at right angles to each other, each of said cutters being provided with a plurality of cutting teeth arranged in concentric rows thereon, said concentric rows being interrupted by spiral channels extending from the apex to the base of their respective cutters, the spiral channels on the said cutters being right and left handed respectively, the teeth thus formed on each cutter having short chisel-like cutting edges lying entirely within the. same conical surface of its respective cutter.

In witness whereof, I have hereunto affixed my signature.

WILLIAM CARLETON STARKEY. 

